Not all pituitary tumors need to be treated right away, especially if they’re not growing or causing problems. But large tumors and those that are clearly growing often do need treatment.

Large tumors

Large tumors (called macroadenomas) tend to cause symptoms and are most often treated with surgery. This helps get rid of the symptoms and reduces the risk of damaging tissues near the pitituitary gland (like blood vessels, nerves, and the brain). Radiation therapy or radiosurgery
might be done after surgery to kill any tumor cells that were left behind.

If a patient is not able to have surgery, radiation may be used as the main
treatment.

MRI scans are done for many
years after treatment. Eye exams and
blood tests may be done, too. If there's tumor re-growth, more surgery or radiation may be used. Drug treatment is usually not helpful in treating these tumors, but medicines used to treat
functional tumors may be tried. Some doctors have reported success using the chemotherapy drug temozolomide for fast-growing tumors.

Incidentalomas

These are small pituitary tumors (called microadenomas) that are seen on scans done for other reasons. They usually don’t cause symptoms because they’re not big enough to press on nearby structures and they don’t secrete high levels of any hormone.

Most of these tumors do not change, and many doctors recommend just watching them. Regular physical exams and yearly MRI scans will be done to see if they start growing. Hormone
levels may be checked, too. If the does tumor start growing or causing symptoms, it can then be treated. But the important point is that people with incidentalomas shouldn’t get tests or treatments that they don't really need.